wifi: ath11k: fix TPE power levels

The chanctx can be shared, but it seems like the TPE values for
this vif should only reflect the channel that the vif uses, which
is captured in bss_conf->chanreq.oper rather than the chanctx.
Use that when calculating defaults, a similar issue is where the
data from the AP is processed, but I'm moving that to mac80211.

Acked-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240506214536.d99fcf5856b9.I359bb401ea74bf82dc981a86a7ca3fa44d169d2e@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>